Pathogenic Th cell subsets in chronic inflammatory diseases

Area of Science:

• Immunology
• Cell Biology

Background:

• CD4(+) T cells are crucial for pathogen defense but can also cause inflammatory diseases.
• Beyond classical Th1/Th2 differentiation, subsets like Th17, Th9, T follicular helper (Tfh), and T regulatory (Treg) cells are recognized.
• Recent research highlights significant plasticity and heterogeneity within T helper cell populations.

Purpose of the Study:

• To review the role of diverse CD4(+) T cell subsets in the pathogenesis of immune-mediated inflammatory diseases.
• To explore unique subpopulations and the molecular mechanisms driving T helper cell plasticity and heterogeneity.
• To propose a new model for immune-mediated inflammatory disease induction and persistence.

Main Methods:

• Literature review focusing on recent advancements in T helper cell subset research.
• Analysis of molecular mechanisms underlying T helper cell plasticity.
• Conceptual model development for disease pathogenesis.

Main Results:

• Identification of multiple CD4(+) T cell subsets beyond Th1/Th2, each with distinct pathogenic roles.
• Elucidation of molecular pathways contributing to T helper cell heterogeneity and plasticity.
• Evidence suggesting T helper cell plasticity challenges the conventional Th1/Th2 balance model.

Conclusions:

• Diverse T helper cell subsets significantly contribute to immune-mediated inflammatory diseases.
• T helper cell plasticity necessitates a revised understanding of disease etiology.
• The proposed 'pathogenic Th population disease induction model' offers a framework for understanding disease initiation and maintenance.